Which substance could be used to put out a fire in a pan of bacon fat?

Baking soda is effective for putting out a grease fire, such as one caused by bacon fat, because it works by smothering the fire. When baking soda is heated, it releases carbon dioxide, which displaces oxygen and can help to extinguish flames. Additionally, baking soda is less likely to spread the fire, which is a significant risk when using substances like water that can cause flaming fat to splatter.

In contrast, water is not suitable for extinguishing grease fires. Adding water can cause the hot fat to splatter violently, potentially spreading the fire. Flour is also not safe as it can ignite and potentially create an explosive reaction. Ice, although it might seem like a cooling agent, would similarly introduce water into the situation, leading to a dangerous outcome. Therefore, baking soda is the most appropriate choice for safely addressing a fire caused by bacon fat.